Work is to be continued on studying the conformations of molecules related to acetylcholine and to local anesthetics in the crystal and in solution. Rotational barriers to conformational changes in such molecules are to be determined. Studies on the active sites of acetylcholinesterase and choline acetyltransferase will continue. On the basis of our recent synthesis of stereospecific conformationally defined diazonium salts related to acetylcholine-receptor sites, a series of enantiomeric fluorescent labelling molecules, photochromic reagents, photo-labelling reagents, thiol-group reagents, and fluorine-substituted molecules are to be synthesized and studied to provide information about the topography of active sites. Improved methods for purifying the "axonal cholinergic binding macromolecule" are to be sought. The relationship between electrical stimulation and susceptibility to inhibition by thiol-reagents in axons will be explored.